IOS NavigateBar Back Button 全局修改的两种方法

IOS全局修改NavigateBar Back Button样式的两种方法：

1，通过[UIBarButtonItem appearance] 的setBackButtonBackgroundImage方法对back按钮样式自定义 但是此方法中设置forState:UIControlStateHighlighted属性无效 设置图片的imageWithRenderingMode阻止系统渲染也没有用（如有错误还望指正）

2，通过自定义NavigationController 重写push方法实现对back按钮的全局修改 当需要在局部控制器设置back 按钮样式时 直接可以覆盖 （推荐此方法）

下面是两种方法的具体实现

1，

UIImage*backButtonBackgroundImage = [UIImageimageNamed:@"navigationbar_back"];

UIImage*backButtonBackgroundImageSelected =[UIImageimageNamed:@"navigationbar_back_highlighted"];

backButtonBackgroundImage = [backButtonBackgroundImageresizableImageWithCapInsets：UIEdgeInsetsMake（0，backButtonBackgroundImage.size.width-1,0,0）];

//设置全局属性

idappearance = [UIBarButtonItem appearance];

[appearancesetBackButtonBackgroundImage:backButtonBackgroundImage forState:UIControlStateNormalbarMetrics:UIBarMetricsDefault];

[appearance setBackButtonBackgroundImage:backButtonBackgroundImageSelected forState:UIControlStateHighlighted bar Metrics:UIBarMetricsDefault];

//将文字隐藏

[appearance setTitleTextAttributes:@{

NSFontAttributeName:[UIFontsystemFontOfSize:0.1],

NSForegroundColorAttributeName: [UIColorclearColor]

}

forState:UIControlStateNormal];

2（推荐此方法）

//首先创建自定义UICustomNavigationController 继承系统的UINavigationController

//重写UICustomNavigationController 的 -(void)pushViewController:(UIViewController*)viewController animated:(BOOL)animated 方法：

@implementation UICustomNavigationController

-(void)pushViewController:(UIViewController*)viewController animated:(BOOL)animated{

[superpushViewController:viewControlleranimated:animated];

//NavigationController中包含的第一个UIViewController也是push方法进来的 但是一般这个controller不需要添加back button 

if(self.viewControllers.count>1) {

UIButton*backButton=[UIButtonbuttonWithType:UIButtonTypeCustom];

[backButtonsetBackgroundImage:[UIImageimageNamed:@"navigationbar_back"]forState:UIControlStateNormal];

[backButtonsetBackgroundImage:[UIImageimageNamed:@"navigationbar_back_highlighted"]forState:UIControlStateHighlighted];

backButton.frame=CGRectMake(0,0,30,30);

[backButtonaddTarget:selfaction:@selector(back)forControlEvents:UIControlEventTouchUpInside];

viewController.navigationItem.leftBarButtonItem=[[UIBarButtonItemalloc]initWithCustomView:backButton];

}

}

//back方法

-(void)back{

[self popViewControllerAnimated:YES];

}

@end

最后创建自定义Back 按钮的UICustomNavigationController

UICustomNavigationController*navVc=[[UICustomNavigationController alloc]  initWithRootViewController:childViewController];